Re: [PATCH bpf-next 02/18] bpf: Add precision marking and backtracking for stack argument slots

Yonghong Song
2026-04-25T05:10:29Z

On 4/24/26 11:00 AM, bot+bpf-ci@kernel.org wrote:
>> bpf: Add precision marking and backtracking for stack argument slots
>>
>> Extend the precision marking and backtracking infrastructure to
>> support stack argument slots (r11-based accesses). Without this,
>> precision demands for scalar values passed through stack arguments
>> are silently dropped, which could allow the verifier to incorrectly
>> prune states with different constant values in stack arg slots.
> This commit appears to be fixing a bug introduced by commit 8ade62ae1543
> ("bpf: Support stack arguments for bpf functions"). Should this commit include
> a Fixes: tag?
>
> Suggested: Fixes: 8ade62ae1543 ("bpf: Support stack arguments for bpf functions")

Not really. See "bpf: Enable r11 based insns". So you can consider this
still a preparation patch.

>
>
> ---
> AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
> See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
>
> CI run summary: https://github.com/kernel-patches/bpf/actions/runs/24902767240